Uncertainties in ground motion prediction in probabilistic seismic hazard analysis (PSHA) of civil infrastructure - Seismic Risk Analysis and Management of Civil Infrastructure Systems - page 52

2.6 Conclusions

Empirical ground-motion modelling is relatively mature yet there are many
enhancements that can be made to the way in which models are derived.
The scarcity of recordings from many earthquake scenarios of interest to
hazard and risk applications has resulted in modelling assumptions being
made that are strictly not appropriate. Many of the issues that have been
outlined in this chapter relate to the need to try to compile a dataset that
provides constraint for the wide range of scenarios considered in these
applications. In a similar manner, the brief discussion of the future trends
actually relate to how one can go about removing some of these assump-
tions as the numbers of high-quality recordings available for use in regres-
sion analyses increases in time.
The most important point to keep in mind when considering ground-
motion models in the context of probabilistic hazard and risk analyses is
that the role of these models is to provide the distribution of ground-motion
amplitudes for given earthquake scenarios. This distribution is defi ned by
two parameters and each of these parameters has a degree of epistemic
uncertainty associated with it. In order to rigorously account for ground-
motion uncertainty within hazard and risk analyses we must account for
these epistemic uncertainties. Traditional approaches based upon logic tree
formulations do not capture the extent of epistemic uncertainty adequately
as they ignore the important contribution of model-specifi c epistemic
uncertainty.

2.7 References

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Atkinson, G.M. & D.M. Boore (2006). Earthquake ground-motion prediction equa-
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Atkinson, G.M. & D.M. Boore (2011). Modifi cations to existing ground-motion
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